Forty years ago, public views about homosexuality were extremely negative in many rich countries. As the chart shows, back in 1984, one in three Dutch people believed homosexuality was “never or rarely justified”. In Spain and Great Britain, that view was held by the majority. Perhaps most strikingly, three-quarters of Americans thought the same.
Could also be interesting what shape the change took. Is it a change in the proportion of people who select 1 and 10? Is is basically normally distributed but the mean shifts? Or both the mean and the variance go down?